Sheet Metal Cover For A Beverage Can, Provided With A Large Perforation

ABSTRACT

A sheet metal cover for sealing the body of a beverage enabling a high internally pressurized beverage can to be formed, wherein said cover is embodied in such a way that it is possible to mount an initially separate re-sealable device. The sheet metal cover can also be configured in such a way as to maintain pressure stability. It maintains stackability and it resembles as close as possible a standard shell, at least in the external edge design thereof, such that modifications in the filling line can be kept to a minimum. The sheet metal cover and a folding edge ( 11 ) which surrounds said panel and which is adapted such that it can be folded onto a peripheral edge of the body of the container and is suitable therefor. The panel has a large dimensioned opening ( 15 ) which is surrounded by an encircling strip ( 15 ) which is axially offset in relation to a plane (E) of the surface of the opening. A reinforcement plate ( 20; 21, 22, 23 ) extending in an extensive and radial manner is provided along at least one peripheral section of the encircling strip ( 16 ).

The invention relates to a lid made from sheet metal for closingcontainer bodies, the content of which is under increased internalpressure, as is known from cans for drinks containing carbonic acid.

In order to be able to easily open such containers, it is conventionalto provide a defined region in the lid panel (panel) of the sheet metallid, which may be broken and hence exposed to the removal opening byexternal pressure. Various designs of the break-open region and variousways of applying the opening pressure are thus known, inter alia fromU.S. Pat. No. 3,361,261 (Fraze) having a trapezium-shaped rip-openregion within a substantially oval area limited by folded lines (there16, 18) at the edges. This rolled-in folded line stabilizes the panel.The oval area within the folded lines is significantly smaller than 30%of the overall panel.

Also in other lids, a limited region is originally closed by sheet metaland is then separated off by the action of a lever flap (tab) at aweakened line and pressed into the closed container. If one would liketo design the can, and thus expressly the lid, to be reclosable, bothsolutions mentioned are not applicable.

Many other solutions in the state of the art are concerned with therecloseability of drinks cans, in particular under external (political)pressure and under internal excess pressure of the closed container. Thepressure stress from both sides requires from the solution of a sheetmetal lid a number of properties which cannot be easily harmonised andcannot be made available on a small surface. Many solutions of the stateof the art which suggest recloseability, achieve this only by losing thestackability of a can. However, the stackability is an original propertyof a closed can which cannot be lost. A can must remain stackable overmany layers without additional elements having to be added. The can mayexperience as few as possible modifying interventions during closing, inparticular in the region of the sheet metal lid, in order to make iteasier for the filler to get involved with a kind or a new type of canlid. Basically, the principle of recloseability must thus be differentwithout a tab (mostly SOT) being arranged on the lid panel. Thusadditional free space is available which was hitherto occupied by thetab. This additional space is situated directly in the lid plane(slightly thereabove).

It is the object of the invention to prepare a sheet metal lid forclosing a drinks can to facilitate assembly of an initially separatereclosing device and to facilitate its assembly on the sheet metal lid.The sheet metal lid should also be designed so that it retains itspressure stability, that it does not lose the stackability and lies asclose as possible to a standard shell in its at least external edgedesign in order to keep changes on a filling line as low as possible.The recloseability of the container should however be facilitated by thelid, since the ironed (by DWI) one-part can body cannot contributeanything to this solution (recloseability) due to its originalproperties.

This object is achieved by claim 1, claim 2 or claim 32 or 33. This lidis manufactured by a method (claim 31).

The invention adds to a solution in which an additional part (areclosing device) is inserted in a “large opening” in the lid panel.This additional part is not to be an object of is this description andbe claimed, but only the sheet metal lid which as such brings with itthe suitability, property and precondition of being combined with such areclosing device in order to then be mounted and rebated on a filledbody as a closure lid by the filler.

The large-dimension opening in the panel (the lid surface) should beunderstood so that it provides a significantly larger opening than isthe case for the regions which can be broken described in theintroduction (claim 1, claim 26). They have only relatively smalldimensions in order to be able on the whole to keep the stability of thepanel.

Indeed LOE closure lids are known (Large opening end), which provide anenlarged opening particularly for Gulp-drinks, which is orientatedtransversely and designed to be reniform, nevertheless not circular dueto the necessity which continues to exist of attaching a tab to the lidsheet metal externally (via a rivet), and also this reniform shape liesonly on one side of the axial centre plane of the lid, see WO 97/30902(ANCC), there FIG. 9.

Using the invention, the opening surface area becomes large. Aperforation is preferably introduced into the lid, the opening dimensionof which goes beyond the lid centre (claim 2). The large-dimensionperforation is not closed by a sheet metal section and also cannot bebroken open via a scored or weakened line, but remains open in order tobe closed later by the reclosing device which has adapted geometry. Itpermits the opening and closing of the flow path in the opened region(the perforation) so that here a “large-dimension opening” will bediscussed further on, which is free for the flow of the drink,controlled by the reclosing device, but which is not to be illustratedhere, see for this in detail PCT/NL2004/00024, filed on 13 Jan. 2004(WO-A 2005/068312).

The sheet metal lid as such is now as before a finally shaped sheetmetal lid originating from a manufacturing method (claim 31). It is morethan a shell (the crude form), it is ready to be combined with thereclosure in order then in this combination to replace a conventionalSOT closure lid which is normal today by a scored line and to close inreclosable manner the bodies closed by it, which are likewise notillustrated here, because they are available according to standard.

An enclosing strip, which is offset in one plane, is provided around thelarge-dimension opening. It serves for stabilisation (claim 1). Astiffening plateau placed radially further outwards, which contributesadditionally to the stiffening of the sheet metal lid, is provided alongat least one peripheral section of this enclosing strip. Due to thelarge-dimension opening, a considerably loss of strength can be expectedin the panel, which is compensated by the enclosing strip and thestiffening surface (stiffening plateau) extending partly peripherallyaround the enclosing strip (claim 33). This is obtained by a staggeredgroup (sequence) of geometric shapes extending clearly in peripheraldirection.

The stiffening plateau preferably extends not further than partlyperipherally and in radial direction, wherein it is orientated to beflat, designed in particular to be part moon-shaped or arcsegment-shaped (claim 3). It may also be described so that it has abulge section with greater radial dimension and two arm sections whichextend peripherally (claim 11). The plateau thus extends in a peripheralangle of more than 180° (claim 12).

Due to a preferably centrally offset arrangement of the large opening(claim 2, 30, 24), there is more remaining lid panel on one side of theopening than on the other side, where the opening extends closer to theperipheral groove. The central offsetting may be in the range between 5%and 25% of the diameter of the lid panel (in each case in thenon-perforated state) depending on the dimensions of the main openingdesigned to be large and intended in most cases to be circular (claim24, 21). A range between 10% and 15% is preferred, relative to the saiddiameter of the panel (lid panel) within the peripheral groove.

This offsetting towards one side (as seen from the centre) makes itpossible to attach the additional stiffening on the other side due tothe stiffening plateau in part moon-shaped or arc segment-shaped design(in short ‘half-moon-like’). It includes at least 90°, preferablyapproximately 180° of the opening and—relative to the lid panel—isdesigned to be encompassing more than 180° (claim 12). Due to thecentral offsetting, space is provided between the one edge of theopening and the peripheral groove to arrange this stiffening.

On the other side remains less sheet metal area than the opening areadefined by the perforation (claim 30).

To outline a large opening, it is possible to start from more than 30%of the surface of the as yet non-perforated lid panel. This dimensionrelates to the surface area which is the square of the radius. If thesize of the opening is related to diameter, the diameter of the opening(for substantially circular design) is greater than 50% of the diameterof the panel, the same also applies to the dimensions of the radii. Arange between 55% and 65% is preferred (claim 5). The opening is atleast essentially round (claim 28) or at least approximately oval. Ithas a free inner edge (claim 36).

Further details regarding the flat extension—seen in radial direction ofthe lid panel—lie in the peripheral strip which surrounds thelarge-dimension opening and leaves between the edge of the opening andthe start of the peripheral strip, a further edge strip which alsosurrounds the opening. This edge strip and the previously mentionedperipheral strip lie in axial direction (vertically to the radialextension) on two different levels, also called height or height levelor height position. The axial direction defines the direction verticallyto the radials in cylindrical coordinates.

Speaking of “inner” and “outer” is avoided for a lid panel, since it isto be described and to be claimed in the state not arranged on the body.

When looking at the figures, it may be assumed that “outer” appears as“top” in the figures, but which is not a restriction with regard to thedescription of the axial height relationships.

By attaching the stiffening plateau partly peripherally to the opening,which is enclosed by the at least one peripheral strip, further partlyperipheral strip geometry is possible, which is designated as a “furtherintermediate strip” (claim 15). It is situated between the outer edge ofthe stiffening plateau and the peripheral groove.

The further intermediate strip and the peripheral strip preferably haveon their peripheral extension, a constant width (claim 16). Due to thestructures extending peripherally and arranged differently, it ispossible to provide changing heights of these structures, which nowrefers to the axial direction of the geometries previously mainlydescribed in radial direction (claim 18, 19).

Observed in cross-section, an up-and-down may be formed, which due tochanging height levels ensures that stiffening occurs which in spite ofthe large-dimension perforation (opening) can extend to the entire lidpanel. A step is thus produced between in each case two adjacent areas.The step may have a piece running diagonally at least in sections, whichleads into the particular next structure via particular radii (claim20).

For the height positions, a datum plane may be defined as a reference(claim 4), which is placed on the plane of the perforation, that is, isplaced in the plane of the opening. Other geometries may be defined inthe other height positions relative to this datum plane (claim 4, claim33).

In such a design, the lid panel, in spite of the destabilising “largeopening”, has high pressure stability and in addition surprisinglycontrolled ‘buckling’, which corresponds to bulging of the lid atexcessive internal pressure. Up to normal pressure and several timesnormal pressure, the lid however remains stable so that a safe sealingon the first peripheral strip may be achieved by the reclosing device(claim 22). It lies reliably at the same height position (at the samelevel along its entire periphery), to ensure a sealing function withrespect to a sealing lip of the reclosing device. In its closing andsealing position the lip presses onto the peripheral strip.

The loss of strength may be reliably compensated. The combination of allstiffening geometries, in particular the features pointed out accordingto claim 1, 2 also achieve controlled ‘buckling’ in the sense of headspace enlargement by increased internal pressure in the closed can. Allrequirements of the lid, the pressure stability, the considerabledependence on standard closures, the stackability and the possibility offacilitating reclosure, indicated in the introduction, are achieved.

The further edge strip may lie at a different height position (claim 7)than the first peripheral strip, preferable deeper (claim 8). Theopening for the said device may contain two opposing flat sections toimprove assembly (claim 10). The flat sections extend radially inwards(claim 10).

The plateau height may preferably be placed above the datum plane (claim13, 4). If the plateau is defined radially inwards and radially outwardsby the two peripheral strips (intermediate strip and enclosing strip),different height levels of these three regions achieve improvedstabilisation (claim 14, 18). Enclosing strip and further intermediatestrip (claim 15) may preferably be placed at the same height (claim 18).

Leading-in of the said further intermediate strip, which does not extendfully peripherally, but only partly peripherally, just like thestiffening plateau, takes place at the arm ends of the stiffeningplateau (claim 17). A leading-in surface, which is designed to beV-shaped or Y-shaped, is formed here.

The surface of the or part moon-shaped stiffening (claim 11) preferablyhas no additional beads on its flat extension (claim 23).

It remains to be said that the modified shell, that is the finishedproduct, which is prepared to receive the reclosing device, has aconstant opening, which is also called perforation, but is not coveredby sheet metal (claim 21). It has no scored or weakened lines (claim4c). Further, no tab (rip-open flap) is attached to the sheet metal(claim 4a).

To compensate for the loss in stiffening in the panel peripherallyextending geometries are used. In the radial direction an up-and-downoccurs along a ray, i.e. a change of height positions (change oflevels), in particular in that region of the lid from which the largeopening is offset (centrally offset) and in which the sickle-shapedplateau area is introduced without additional stiffenings or beads.

The staggered change in height levels occurs from radially inward toradially outward, beginning with the inner edge strip (around the largeopening) to the first enclosing strip, to the stiffening plateau, to thefurther intermediate strip and finally via the peripheral groove to thefolding or mounting edge. Between the stiffening regions which extendperipherally over at least 90° preferably diagonal steps are arranged.

The invention is illustrated and supplemented below using exemplaryembodiments.

FIG. 1 is a plan view of a lid as one of several first examples.

FIG. 2 is an axial section A-A through the lid according to FIG. 1.

FIG. 3 is a further example with two axial sections A-A, B-B through thelid offset by 90°.

The lid 1 shown in FIGS. 1 and 2 as a first example of the invention isintended for a conventional drinks can body, which is not shown. The lidis made from sheet metal having a thin wall thickness, as generallyconventional.

It has a lid panel 10 (as a panel) and a folded edge 11 for connectionwith an appropriate container. A damping bead 12 (peripheral groove),which defines the lid panel 10 radially outwards, runs along the foldededge. An ironed body is generally known and does not need to bedescribed. It has an upper body edge, which is formed radially outwardsas a flange and is closed by the folded edge 11 by a folding device(flanging roller) to form a multiple fold, mostly by the filler.

The folded edge 11 is arranged radially outside of the damping bead 12,which is also called “peripheral groove”, and projects beyond the lidpanel 10 at axial height. The lid panel 10, itself also called a“panel”, is designed to be circular overall, but due to the opening 15emerging significantly in size, which forms a cutout, essentiallycircular perforation in the lid panel, is still only partly present.

The cylindrical coordinates are used for the description, in radialdirection (horizontal direction), the extension of the lid panel and invertical or height direction, vertically to the plane E according toFIG. 2, the axial direction.

The body itself is not shown, also the reclosing device 90 to beintroduced into the opening 15 and to be assembled there on the edge, isnot shown separately.

The opening 15 in FIG. 1 is shown with large dimensions in plan view. Itis arranged off-centre, relative to its central point M15, which isoffset with respect to the central point M10 of the panel 10 by ΔM.Offsetting is selected to be between 5% and 25% in several exemplaryembodiments, in the exemplary embodiment shown, it is in the rangebetween 10% and 12% to 15%, in each case relative to the diameter d10 ofthe panel 10, which extends within the peripheral groove 12. As shownd10 is 2·r₁₀.

The diameter as an example of an opening dimension d15 with 2·r15 of theperforation shown here in the example to be essentially circular issmaller than the diameter d10 of the panel 10, but greater than 50% ofthis opening dimension, which underlines the significant size of theopening 15.

A first and a second peripheral strip surround the opening 15. The firstperipheral strip 16 a borders directly on the edge of the opening andhas two segment-like flat sections 15 b, 15 a at the inner side, whichare opposite. They serve to improve assembly of the reclosing device 90.The second peripheral strip 16 has a radial dimension r16, which isgreater than that of the first peripheral strip. It is formed in heightdirection above the plane E.

The plane E is placed in the opening 15 in horizontal direction andforms the comparison standard for height comparisons. It is the plane ofthe opening 15, a two-dimensional extension within the plane is theopening surface. It describes the dimension of the opening 15.

The peripheral strip 16 transfers via a gentle, in particular diagonallyplaced step 16′ into the inner peripheral strip 16 a. The elevatedperipheral ring 16 forms an annular pressure and support surface for asealing and closing lip of the reclosing device 90 lying entirely at thesame level.

The enclosing strip 16 runs completely around the opening 15 anddelimits with respect to the peripheral groove on the left-hand side inFIG. 1. On the right-hand side in FIG. 1, it forms the limit to aplateau 20 designed to be sickle-shaped or part moon-shaped, whichextends only partly peripherally around the perforation 15. It is placedin that region of the lid panel, from which the opening 15 has beendisplaced in centre-offset manner. It is on the right side of the firstaxial centre plane extending vertically to A-A and through M10.

The partial enclosure is essentially 180° for circular design relativeto the opening 15. The peripheral extension of the sickle-shaped plateau20 is greater than 180°, in particular in the range between 200° and240°, in particular in the region of 210°±3%, relative to the peripheryof the lid panel and the peripheral groove 12.

This is produced from two arms 21, 22 extending peripherally, which formthe ends of the stiffening plateau. The stiffening plateau has betweenthese two ends 21, 22, a bulge 23, which has its greatest radialextension in the central plane A-A and is tapered like an arc towardsthe ends 21, 22.

A further intermediate strip 17, which has essentially the same width onits peripheral extension, is provided between the plateau 20 and theperipheral groove 12. The peripheral extension corresponds to theextension of the arc of the plateau 20 and is in any case greater than90°.

The two peripheral strips 16 and 17 have essentially the same width,designated in FIG. 1 by r6 and r7. They also have essentially the sameheight position, easily seen in FIG. 2 with respect to the plane E.

Both the peripheral strip 16 and the peripheral strip 17 transfers via apreferably diagonal step 16″ and 17″ into the plateau region 20, whichlies at a deeper level, preferably slightly above the plane E in FIG. 2.

An edge 20′ of the arc-shaped plateau 20 corresponds to these steps 16″and 17″ and is designed as a preferably diagonal step in each case withat least one short diagonal section and two radii to pass over into thein each case adjacent region. These diagonals 20′ form stiffenings. Alsothe change between higher and lower positions (relative to a heightdirection), observed in a radial direction, on a “radius vector” (ray)from the centre M15, forms a stiffening.

Leading-in of the outer peripheral strip 17 into the inner peripheralstrip 16 takes place in the two lead-in zones 17 b, 17 a, which aredirectly adjacent the arm ends 21, 22 of the plateau 20. Y-shaped orV-shaped zones are formed here, which are wider than the particularstrip shape of the peripheral strips 16, 17.

To illustrate the dimension of the opening 15, reference should be madeto the radii. The internal radius r15 of the opening is shown incomparison to the radius r10 of the lid panel. The one or the otherradius starts in each case from the centre M15 or M10. The radius r15 isthus greater than half the radius of r10, in particular in the rangeabove 60% between 60% and 65% of the main radius of the lid panel. Thisdescribes a large opening. The man skilled in the art will understand“large” here in an optical relation to the size of break-open regions ofdrinks can lids normally expected to the priority date. When the manskilled in the art of cans compares the lengths of the radii, he wouldimmediately say concerning r15: “This has been chosen quite large”.

Relative to surfaces, it is possible to convert to the surfaces via theradii, (quadratic influence), wherein the surface of the opening 15 isgreater than 30% of the panel surface 10, relative to the original size(without perforation 15). Here too, a large design of the opening isround about 40%, preferably between 35% and 45% of the non-perforatedpanel surface.

These dimension details are also maintained within the framework of ΔMcentral offsetting, which can be seen from the central points M10 andM15. Here, a reference to the diameter d10 (double main radius) ishelpful regarding the size detail.

The central offset ΔM in various exemplary embodiments, which are notall shown separately, lies between 5% and 25%. They change inasmuch asthe size of the opening 15 also has a clearance and range, and the shapeof the opening also has a clearance and range, which may deviate fromthe exact circular shape, for example polygonal or oval. It is at leastapproximately polygonal or oval.

In a preferred range, the ΔM central offset lies between 10% and 15%.

All these measures express that it is—as understood by the man skilledin the art—a large opening 15 relative to such openings which areprovided or “expected” by the man skilled in the art in normal drinkscan lids.

To compensate the stiffening loss, the geometric shapes are used whichhave been described previously. An up-and-down is produced in radialdirection, that is a change in height positions (level change), inparticular in that region of the lid the opening 15 is displaced(centre-offset) from and in which the sickle-shaped plateau surface 20is introduced without further additional stiffenings or additionalbeads.

The change of height positions takes place from radially inwards toradially outwards (in a staggered form), starting from the inner edgestrip 16 a (around the opening 15), to the first enclosing strip 16, tothe stiffening plateau 20, to the further intermediate strip 17 andfinally via the peripheral bead 12 to the peripheral edge 11. Diagonallyrunning steps are preferably arranged between these areas, as previouslydescribed using the step 20′ of the stiffening plateau 20 (as anessentially flat surface having a large extension).

The change of height levels of the geometric stiffening shapes 16 a, 16,20, 17, 12, 11 can be seen in section in FIG. 2. Each of the stiffeninggeometries extends peripherally over at least 90°, as subsidiary linesC-C in FIG. 1 illustrate. They define an angle of 90° and allstiffenings extend far beyond it in peripheral direction, reaching 180°and even 360° for individual peripheral stiffenings.

The opening 15 is not covered by sheet metal, but is open. It has a freeinner edge 15 a. It is centre-offset (relative to the diameter of thepanel) between 5% and 25% and the first enclosing strip 16 surroundingit reliably retains the same height position to facilitate a sealingfunction.

The further exemplary embodiment according to FIG. 3 follows the firstexemplary embodiment with two sections A-A, B-B.

It is shown here that in the transverse direction B-B (the centralplane), a change in height level also takes place from radially inwardsto radially outwards, as far as the sickle 20 extends. Otherwise thanrelative to the central plane A-A, the opening 15 is symmetrical intransverse direction, so that left and right edge have the same distanceto the peripheral groove 12. Relative to the central plane B-B, however,there is asymmetries The perforation 15 with its free edge 15 a isoffset to a large extent towards the first side (this side) of thecentral plane so that on the other side (the other side) there is largespace for extensive stiffening geometries.

The remaining descriptions regarding FIG. 3 may be assumed from thepreceding exemplary embodiment.

The height difference h1 of outer peripheral strip 17 and innerperipheral strip 16 is measured with respect to the deeper-lyingsickle-shaped plateau surface 20 according to the section A-A.

1. Sheet metal lid (1) for closing a container, such as a drinks canbody, under increased internal pressure in the closed state, which sheetmetal lid has a panel (10) and a folded edge (11) surrounding the panel,which is adapted and suitable for rebating on an annular edge of thecontainer body; wherein (a) the panel (10) has a large-dimension opening(15), which is surrounded by an enclosing strip (16), which is axiallyoffset with respect to a plane (E) of the opening surface; (b) astiffening plateau (20; 21, 22, 23)—extending peripherally andradially—is provided along at least one peripheral section of theenclosing strip (16).
 2. Sheet metal lid for closing a container, suchas a drinks can body, under increased internal pressure in the closedstate, and for mounting or for assembly of a reclosing device (90), butnot containing this; (c) wherein the sheet metal lid has a panel or alid surface (10) radially within a peripheral groove (12) and anassembly edge (11) outside of the peripheral groove (12); (d) whereinthe panel has an off-centre—relative to the panel—opening (15, ΔM), theopening dimension (d15, r15) of which being greater than 50% of adiameter (d10, r10) of the panel (10).
 3. Sheet metal lid according toclaim 2, wherein a part moon-shaped or arc segment-shaped stiffeningsurface (20, 21, 22, 23) is arranged on one side of the opening (15),which is further away from the peripheral groove (12) due to theoff-centre arrangement than an opposite side of the opening (15). 4.Sheet metal lid according to claim 1 or 2, wherein the opening (15)establishes a datum plane (E) of the lid panel (10), with respect towhich the folded edge or assembly edge (11) is raised axially and withrespect to which the peripheral groove (12) is lying axially deeper. 5.Sheet metal lid according to claim 1 or 2, wherein the size of theopening occupies more than 30% of the surface of the lid panel (10)within the peripheral groove (12), in particular its diameter hasdimensions between 55% and 65% of a diameter of the lid panel.
 6. Sheetmetal lid according to claim 1 or 4, wherein the enclosing strip (16)has an inner edge portion, which has a radial distance from an outeredge of the opening (15), to form a further inner edge strip (16 a). 7.Sheet metal lid according to claim 6, wherein the further edge strip (16a) lies at a different height position or plane than the firstperipheral strip (16).
 8. Sheet metal lid according to claim 1, 2 or 7,wherein the first peripheral strip (16) lies axially higher than thedatum plane (E) of the opening surface.
 9. Sheet metal lid according toclaim 8 or 6, wherein the first enclosing strip (16) runs on aperipheral angle of 360°.
 10. Sheet metal lid according to claim 6,wherein at least two opposing surface regions in the further edge strip(16 a) are flattened (15 a, 15 b) inwards.
 11. Sheet metal lid accordingto claim 1, wherein the stiffening plateau (20) is designed like asickle, having a central bulge (23) and two peripherally extending arms(21, 22).
 12. Sheet metal lid according to claim 1, wherein thestiffening plateau (20) extends on more than 180° peripheral angle, inparticular on a peripheral angle greater than 200°, relative to theperiphery of the panel (10).
 13. Sheet metal lid according to claim 1 or4, wherein the stiffening plateau (20), observed in axial direction, isplaced above the datum plane (E).
 14. Sheet metal lid according to claim1 or 13, wherein the stiffening plateau (20) has a height position,which lies axially deeper than that of the enclosing strip (16). 15.Sheet metal lid according to claim 1, 2 or 11, wherein the or astiffening plateau (20) borders (i) on the or a first enclosing strip(16) towards the opening (15); (ii) borders on a further intermediatestrip (17) towards the peripheral groove (12).
 16. Sheet metal lidaccording to claim 15, wherein the further intermediate strip (17) hasessentially the same width along its peripheral extension.
 17. Sheetmetal lid according to claim 16 or 15, wherein the further intermediatestrip (17) on each peripheral end (21, 22) of the stiffening plateau(20) leads (17 a, 17 b) into the first enclosing strip (16).
 18. Sheetmetal lid according to claim 15, wherein the further intermediate strip(17) and the first enclosing strip (16) are placed in each case at adifferent axial height position than the stiffening plateau (20), inparticular are both placed axially higher than the datum plane (E) ofthe opening (15).
 19. Sheet metal lid according to claim 1 or 2, whereinin radial direction, axial height levels of in each case adjacent areasextending at least partially in peripheral direction (16 a, 16,20,17,12) are different, in particular radially inwards to radiallyoutwards starting from a further edge strip (16 a) around the opening(15), over the first enclosing strip (16), the stiffening plateau (20)or the part moon-shaped stiffening surface (20), a further intermediatestrip (17) and the peripheral groove (12), wherein the height levelshave an up-and-down.
 20. Sheet metal lid according to claim 18 or 19,wherein a transition zone, in particular in the form of a diagonallyrunning step (20′) in each case, is arranged between in each case twoadjacent areas (16, 20; 20,17).
 21. Sheet metal lid according to claim 1or 2, which has the opening as a pre-punched opening (15) in the lidwhich is not covered by sheet metal for mounting or assembly of areclosing device (90), wherein the enclosing strip (16) is adapted orprovided for sealing using the device.
 22. Sheet metal lid according toclaim 1 or 2, wherein the enclosing strip (16) has a constant heightposition along its periphery.
 23. Sheet metal lid according to claim 1or 2, wherein the stiffening plateau or a stiffening surface (20) has nofurther beads or depressions on its flat extension.
 24. Sheet metal lidaccording to claim 2, wherein the off-centre mounting (ΔM); M10, M15) ofthe opening (15) is between 5% to 25%, in particular in the range of 10%to 15%, relative to the diameter (d10) of the lid panel (10).
 25. Sheetmetal lid according one of the preceding claims, wherein the reclosingdevice (90) is definitely disclaimed.
 26. Sheet metal lid according toclaim 1, wherein the large opening—as understood by the man skilled inthe art—is evaluated in relation to the “size normally expected indrinks can lids” and is in particular more than 30% of the surface ofthe as yet non-perforated overall surface of lid panel.
 27. Sheet metallid according to claim 1 or 2, wherein no rip-open flap is attached tothe lid panel (10) to break open an opening region.
 28. Sheet metal lidaccording to claim 1 or 2, wherein the opening (15) is at leastapproximately circular or oval, in particular neither rectangular nortrapezoidal.
 29. Sheet metal lid according to claim 1 or 2, notcomprising a scored or weakened line surrounding an opening region whichcan be broke open in a portion.
 30. Sheet metal lid according to claim 1or 2, wherein the size of the opening (15) is dimensioned such that itextends beyond the centre of the panel, the opening surface on this sideof the centre (M10) being greater than the remaining panel surface onthis side of the centre (M10).
 31. A method for producing a sheet metallid for closing a container body, such as a drink can body, underincreased internal pressure in the closed state, which sheet metal lidhas a lid panel (10) and a folded edge (11) surrounding the panel, whichis adapted and suitable for rebating on an edge of the container body;wherein (a) the lid panel (10) is arranged radially within a peripheralgroove (12) and a free opening (15) extending beyond its axial centralplane (B-B) is provided; (b) a stiffening plateau (20; 21, 22,23)—extending peripherally and radially—is stamped radially within theperipheral groove (12) between the peripheral groove and the freeopening (12,15) along at least a peripheral section.
 32. Sheet metal lid(1) for closing a container body, such as a drinks can body, underincreased internal pressure in the closed state, which sheet metal lidhas a lid panel (10) and a folded edge (11) surrounding the panel, whichis adapted and suitable for rebating on an circumferential edge of thecontainer body; (a) wherein the panel has an opening (15) extendingbeyond both central planes (A-A, B-B) which are vertical to each other,the opening being surrounded by an enclosing strip (16) which is axiallyoffset in relation to a plane (E) and has a height level remaining thesame over its entire periphery for sealing and pressing purposes; (b)comprises along at least a peripheral section of the enclosing strip(16) a stiffening plateau (20; 21, 22, 23) extending peripherally andradially, the peripheral extension being greater than 90° (C-C) andreaching in particular to at least 180°.
 33. Sheet metal lid for closinga container body, in particular a drinks can body, under increasedinternal pressure in the closed state, and for mounting or for assemblyof a reclosing device (90), but not containing this; (c) wherein thesheet metal lid has a panel (10) radially within a peripheral groove(12) and a rebatable assembly edge (11) is provided radially outside ofthe peripheral groove (12); (d) wherein the panel (10) has anoff-centre—relative to the panel—opening (15, ΔM), the opening dimension(d15, r15) of which being considerable; (e) the weakening in the panelregion with a greater extent of remaining lid sheet metal caused by theconsiderable size of the opening (15, r15, d15) being counteracted by astaggered group of stiffenings (16 a, 16, 20, 17) extending inperipheral direction, which have from inside to outside a change ofheight positions so as to form an up-and-down along a radial ray.
 34. Amethod according to claim 31, wherein the opening (15) is provided bycutting perforation.
 35. A method according to claim 31 or 34, whereinthe opening is essentially round.
 36. A method according to claim 31,wherein around the opening (15) an enclosing strip (16) is stamped,which strip has a height position remaining the same over the periphery.37. Sheet metal lid according to claim 1 or claim 2, wherein the freeopening (15) has a free inner edge (15 a), in particular without abuckled web projecting downward from the inner edge.